Twitter acquires interactive mobile ad company CrossInstall for an undisclosed sum as Twitter rebuilds its ad server (Allison Schiff/AdExchanger)

Allison Schiff / AdExchanger:
Twitter acquires interactive mobile ad company CrossInstall for an undisclosed sum as Twitter rebuilds its ad server  —  Twitter really wants a piece of the performance advertising pie.  —  On Tuesday, Twitter said it has acquired interactive mobile ad company CrossInstall.  No deal price was disclosed.